As an electromagnetic vibrating pump for sucking and discharging a fluid utilizing the vibration of a vibrator which is equipped with a permanent magnet based on magnetic interaction of an electromagnet and the permanent magnet, there has been conventionally a pump described in FIG. 21 (for example, Japanese Unexamined Patent Publication No. 270556/1996).
The pump is a diaphragm pump and composed of an electromagnet which is arranged facing a frame in a pump frame body 200, a vibrator equipped with a permanent magnet, a diaphragm linked with both ends of the vibrator and pump casing portions which are respectively fixed at both end sides of the above-mentioned frame. Further, the upper portion of the above-mentioned pump frame body 200 is provided with a dust collecting portion 201 for removing such as sand dust and dust in the air and for sucking air. As shown in FIG. 22, the dust collecting portion 201 is composed of a filter 203 which is made of a non-woven cloth of a synthetic fiber and provided in turn in a nearly square or nearly circular dust collecting chamber 202 which is formed in the pump frame body 200, two divisional filter packings 204 and a filter cover 205. Further, a sucking orifice for sucking air is provided at the bottom portion of the above-mentioned dust collecting chamber 202 and an intake 206 of air of the atmosphere is formed between the two divisional filter packings 204 covered with the filter cover 205.
In such arrangement, after air of the atmosphere is sucked from the intake 206, dust is collected with the filter 203, and then the air flows in the pump chamber of the above-mentioned pump casing portions. However, fine dust and fine sand dust which pass the filter 203 cannot be completely removed. Accordingly, there has been a problem that fine sands which pass the filter enter into a gap between a diaphragm being used for a pump and a metal fitting retaining the diaphragm, and the diaphragm is damaged during operation and its life time is shortened. Further, there has been a problem that the number of times of maintenance working for exchanging the diaphragm is increased and the rate of operation of the pump is lowered.